US3778231A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing silicon nitride articles
Assignee: Birmingham Small Arms Co Ltd
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Filing: 1971-03-11
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Granted: 1973-12-11
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Expires: 1991-03-11
Abstract
Abstract A method of producing a silicon nitride article comprising forming an article as a compact of silicon powder, sintering the silicon compact in an atmosphere substantially free of nitrogen, machining the silicon compact to a required accuracy, and nitriding the machined silicon compact to produce the silicon nitride article.
Inventors
- 👤 R Taylor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:52
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/591
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
30 words
A process for producing a silicon nitride article according to claim 1, wherein the silicon compact is sintered in an atmosphere of inert gas such as argon, hydrogen, and helium.
Claim 2
Dependent Claim
26 words
A process for producing a silicon nitride article according to claim 1, wherein the machined silicon compact is nitrided at a temperature between 1,180*C and 1,450*C.
References Cited (Backward Citations)
US3222438A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |